Accessibility/Checklist: Difference between revisions

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*>Frederik.gladhorn
*>Frederik.gladhorn
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== Screen Reader ==
== Screen Reader ==
As a sighted person you will probably never fully understand how users use screen readers. You will most likely not become proficient and efficient in their use. Nonetheless there is a lot you can help to make applications accessible to screen reader users. We refer to screen readers and other assistive technology often as AT.


;[[Development/Tutorials/Accessibility/Screen_Reader_Setup|Setup Screen Readers with KDE]]
;[[Development/Tutorials/Accessibility/Screen_Reader_Setup|Setup Screen Readers with KDE]]
:Gives detailed setup instructions for screen readers.
:Gives detailed setup instructions for screen readers.


More advanced would be the usage of assistive technology. I think we need to  
=== Testing ===
learn from people with actual need of these technologies in order to get a  
This section gives a quick intro what to look for when testing an application with a screen reader.
good grasp of the issues. I can try to write down some issues I know about.


1 Get Orca to work in general - just grab the gnome-orca package that should
be in pretty much any distro and try it with some gtk app. Test that it reacts
to focus changes.
2 Make sure it's using dbus. That means having libatspi 2.0 (package name may
vary, see also the settings here:
http://labs.qt.nokia.com/2011/08/23/accessibility-on-linux/)
3 Have Qt 4.8 and the qt-at-spi bridge.
4 export QT_ACCESSIBILITY=1 (this is needed for Qt 4, fixed in Qt 5)
5 Run the KDE/Qt application you want to test with the Qt version for which
you have the bridge installed. (This works even with Qt built separately in
the home directory and the bridge installed there.)


Once you have an application running with the screen reader:
Once you have an application running with the screen reader:
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bridge still.
bridge still.


Apart from the bridge probably still lacking features and having a few bugs, I
=== Fixing missing information ===
think now it's mostly time to fix up the small missing bits.
Once you found a bug it's usually quite easy to fix. This section explains how to go about improving applications.
 
For many things there are usually easy fixes involving no advanced programming skills but just fixing some details.
 
For this tutorial we assume that you are dealing with a QWidget that is seen by the AT but does for example give not enough information.


Fixing stuff: the good news is that it's really easy usually, no heavy C++
There are two important properties that every QWidget has: an "Accessible Name" and an "Accessible Description".
skills required.
The name is short, for example the label on a button. It should always  
There are two important properties that every QWidget has: AccessibleName and  
AccessibleDescription.
The name is a short label, for example the label on a button. It should always  
be short. The description on the other hand is the more verbose "this button  
be short. The description on the other hand is the more verbose "this button  
does foo and then bar".
does foo and then bar". Qt will try hard to return something for the name. In case of a button, usually the text on the button is returned. But if your button has text that makes only sense when seeing the arrangement of buttons, or only has an image as label, you need to help the AT read the button.
Fire up Qt designer if the app uses .ui files, you'll find the properties and
If you don't, it will only say the type of the widget, "Button" is not a very helpful information.
can type the name/description right in.
If the widget is managed in code, just find the right place and set them:
button->setAccessibleName(i18n("Open"));
button->setAccessibleDescription(i18n("Opens a file dialog to select a new
foo"));


Sometimes you also want to override the label for a different reason. One of my
==== Fixing Accessible Name and Description ====
test apps was the calculator example from Qt. It has a memory recall button
Fire up Qt designer if the app uses .ui files. You'll find the properties and
labelled "MR". Orca will insist on this being the "Mister" button, unless told
can type the name/description right in. After saving the file, rebuild and install the application. You are done, submit a patch to fix the ui file.
otherwise. Of course I couldn't fix that one since it made me smile every
single time ;)


I bet there's more, but this is a beginning. In the end it would be great to  
If the widget is created in the code, just need to find where.
build up a bit of a community that starts using these applications on a  
Once you found the widget, usually where it's created, add some code to it:
regular basis.
button->setAccessibleName(i18n("Open"));
button->setAccessibleDescription(i18n("Opens a file dialog to select a new foo"));
Send your patch.


Should we gather these and extend them on some wiki? I'd love to have some
Sometimes you also want to override the label for a different reason. One of my test apps was the calculator example from Qt. It has a memory recall button labelled "MR". Orca will insist on this being the "Mister" button, unless told otherwise.
accessibility testing going on some time in the future.

Revision as of 00:29, 21 January 2012

Introduction

Fonts and Colors

Many users have some deficiencies when it comes to seeing. This doesn't always mean that they are blind. For some people it is enough when fonts are clear and the color scheme can be adjusted. This is something every application should do in any case, so here is the list:

  • Follow the user interface guidelines! This will get you quite far.
  • Check that color scheme changes apply
    • Try switching to a dark color scheme and see that your application is still usable
  • Test changing the font size
    • Switch to different fonts and see that they apply
    • Increase the font size and make sure that the application layout still works

Keyboard

When you have problems seeing, the mouse is quite hard to use. The keyboard is a lot more reliable. Therefor it is important that applications can be used with the keyboard. For some users, using a mouse is difficult because of motor skill issues. Making applications keyboard accessible benefits everyone, since it allows us to use shortcuts to use the applications more efficiently.

  • Try to operate your application with the TAB key
    • Make sure that the tab order is correct (or fix it in Qt Designer or the code)
  • Start your application and do a common task without using the mouse
    • Note where you had trouble and think about possible improvements in the UI or keyboard shortcuts that are missing

Screen Reader

As a sighted person you will probably never fully understand how users use screen readers. You will most likely not become proficient and efficient in their use. Nonetheless there is a lot you can help to make applications accessible to screen reader users. We refer to screen readers and other assistive technology often as AT.

Setup Screen Readers with KDE
Gives detailed setup instructions for screen readers.

Testing

This section gives a quick intro what to look for when testing an application with a screen reader.


Once you have an application running with the screen reader: Make sure Orca says something intelligible for all elements. When it reads a gui element it should say the label and type, eg: "File, Menu" or "OK, Button". When you have a button that does not have a label, maybe because it shows a picture only, that's something to fix. Try navigating the more troublesome elements - comboboxes and lists and such. Trees need a bit of love in the bridge still.

Fixing missing information

Once you found a bug it's usually quite easy to fix. This section explains how to go about improving applications.

For many things there are usually easy fixes involving no advanced programming skills but just fixing some details.

For this tutorial we assume that you are dealing with a QWidget that is seen by the AT but does for example give not enough information.

There are two important properties that every QWidget has: an "Accessible Name" and an "Accessible Description". The name is short, for example the label on a button. It should always be short. The description on the other hand is the more verbose "this button does foo and then bar". Qt will try hard to return something for the name. In case of a button, usually the text on the button is returned. But if your button has text that makes only sense when seeing the arrangement of buttons, or only has an image as label, you need to help the AT read the button. If you don't, it will only say the type of the widget, "Button" is not a very helpful information.

Fixing Accessible Name and Description

Fire up Qt designer if the app uses .ui files. You'll find the properties and can type the name/description right in. After saving the file, rebuild and install the application. You are done, submit a patch to fix the ui file.

If the widget is created in the code, just need to find where. Once you found the widget, usually where it's created, add some code to it:

button->setAccessibleName(i18n("Open"));
button->setAccessibleDescription(i18n("Opens a file dialog to select a new foo"));

Send your patch.

Sometimes you also want to override the label for a different reason. One of my test apps was the calculator example from Qt. It has a memory recall button labelled "MR". Orca will insist on this being the "Mister" button, unless told otherwise.